Thank you for your question
My name is ***** ***** I shall do my best to help you.
I am so sorry for your troubles
Yes if you are able to pay of all the arrears then the Court will not make the Possession Order.
If your sister is not well enough to attend court then you shoudl go with evidence of her medical condition and a letter from her asking you to deal with matters for her.
Technically this should NOT be enough to allow you to speak for her - but in the circumstance I believe the court will flexible.
At worst the Court make make a suspended possession Order dependent on your clearing the arrears within 14 days
I hope that this is of assistance - please ask if you need further details